1. Field of the Invention
The present invention relates to a charged particle separation apparatus and a charged particle bombardment apparatus.
2. Description of the Related Art
Gas clusters into which plural atoms and the like are condensed exhibit a unique physicochemical behavior, and attract attention for applications in various fields of technologies. Namely, gas cluster ion beams are thought to be applicable for processes such as ion-implantation, surface machining, and thin film deposition in a depth range of several nanometers from a surface of a solid material, while the processes in such a depth range have been considered difficult by conventional technologies.
In a gas cluster generating apparatus, it is possible to generate gas clusters formed of several hundred through several thousand atoms from a compressed gas supplied from a gas supplying source. The number of the atoms in the gas cluster generated by the gas cluster generating apparatus is stochastically-distributed, and thus the gas clusters range in mass. The gas clusters need to be separated depending on the masses of the gas clusters in practical use.
To this end, a method has been proposed in order to separate the gas clusters generated by the gas cluster generating apparatus depending on the masses (Patent Document 1).
Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2005-71642.
The method of separating ionized gas clusters, which is described in Patent Document 1, employs two plate-like electrodes arranged in parallel with each other, and applies electric fields between the two plate-like electrodes in order to separate ionized gas clusters.
When the gas clusters collide against the plate-like electrodes, they may be decomposed, which causes an increase in pressure between the plate-like electrodes. As a result, pressures become different in areas near the plate-like electrodes from areas away from the plate-like electrodes, which may affect separation performance of the ionized gas clusters.
The present invention has been made in view of the above, and provides a charged particle separation apparatus and a charged particle bombardment apparatus that enable appropriate separation of ionized gas clusters depending on a mass or a valence of the ionized gas clusters.